The Research On Reduction PAPR In OFDM System

The Orthogonal Frequency Division Musltiplexing (OFDM) is one of the multi-carriermodulation technologies. Because of its excellent fading resistances, the interference ofInter-carriers, higher spectral efficiency and other advantages, OFDM has become one of thekey technology of the next generation mobile communication. However, OFDM exhibits thehigher peak to average power ratio (PAPR) is one of the maximum fatal weakness. The largerPAPR will decrease the precision of system hardwares and the serious signal distortion, sohow to reduce the PAPR of the OFDM system can affect the whole system directly.This article leads to the OFDM technology through the background of the multi-carriermodulation technology, and study its principle in detail include the key technology.theadvantages and disadvantages etc.Special its several important technologies include thelimiting amplitude technology, the coding technology, the probability technology which usethe experimental simulation.The article alse summarizes the advantages and disadvantages ofthe each techniques.The article study the partial transmit sequence (PTS) algorithm in detail. Based on bothof the system performance and the computational complexity. First, simulation analys theiterative algorithm to reduce the computational complexity.Secondly, from different point ofview present two kinds of new algorithms. One of them is based on the real and imaginaryparts of the joint optimization to improve PTS algorithm about the performance of the system;the other is based on the power of judgment to improve PTS algorithm about reducingsystem’s computational complexity without affecting the system performance; The last, thispaper presents the iteration method and the power of judgment method to further improve thereal and imaginary part of the joint optimization PTS algorithm. In this paper the newalgorithms are not only made a theoretical analysis,And also done a lot of experimentssimulations and performance analysis, Proved as long as the right Parameters selection, thenew algorithms can futher improve the PAPR performance of the system.According todifferent systems select appropriate algorithm to improve the OFDM system performance.